Circular No. 5376 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN PERIODIC COMET SHOEMAKER-LEVY 5 (1991z) The following precise positions, measured by C. S. Shoemaker and J. Alu from exposures with the 0.46-m Palomar Schmidt, involve prediscovery images identified by Shoemaker on films obtained by H. E. Holt, T. M. King, K. Lawler, J. Stiffler and K. W. Zeigler (Sept. 12, 17), images from films obtained by Shoemaker, E. M. Shoemaker and D. H. Levy (Oct. 4, 8) and by K. Lawrence, P. Rose and R. Bambery (Oct. 11, 14): 1991 UT R.A. (1950) Decl. m1 Sept.12.36510 0 38 08.09 - 8 18 36.3 16.5 17.41823 0 35 02.24 - 8 10 18.2 17.46997 0 35 00.07 - 8 10 11.9 Oct. 4.35469 0 21 56.65 - 7 20 57.4 16.0 8.25035 0 18 46.74 - 7 03 13.1 11.27378 0 16 23.64 - 6 47 28.6 16 11.29844 0 16 22.34 - 6 47 19.9 14.28264 0 14 07.82 - 6 30 06.5 14.30747 0 14 06.72 - 6 29 55.9 Improved orbital elements from 14 observations Sept. 17-Oct. 14: T = 1991 Dec. 13.2346 ET Peri. = 6.0372 e = 0.529856 Node = 28.9889 1950.0 q = 1.984423 AU Incl. = 11.7562 a = 4.220888 AU n = 0.1136576 P = 8.672 years 1991 ET R.A. (1950) Decl. Delta r m1 Oct. 11 0 16.60 - 6 48.9 1.087 2.062 16.4 21 0 09.66 - 5 44.9 31 0 05.05 - 4 22.5 1.140 2.021 16.4 Nov. 10 0 03.46 - 2 43.7 20 0 05.19 - 0 51.3 1.264 1.995 16.5 30 0 10.13 + 1 11.4 Dec. 10 0 17.98 + 3 22.0 1.437 1.985 16.8 20 0 28.40 + 5 38.2 30 0 41.00 + 7 57.9 1.641 1.990 17.1 1991 October 24 Daniel W. E. Green